RESUMO
Healthy subjects (15-50 years old) were randomised to receive, intramuscularly, 10 or 20 micrograms of a yeast-derived recombinant hepatitis B vaccine (Heberbiovac HB) on a two-dose (0-1) schedule. Anti-hepatitis B surface antigen antibodies (HBsAb) were determined at 2, 3 and 6 months. Twenty micrograms immunisation yielded 96.3% seroprotection (HBsAb >10 IU/l) at t=3, which persisted to 97.2% at t=6. The 10 microgram group resulted in 87.4% seroprotection at t=3 and 81% at t=6, but reached >95% among subjects <21 years old, both at t=3 and 6. It is concluded that the vaccine used is highly immunogenic and the two-dose 20 microgram immunisation can be used in all age groups and 10 micrograms in subjects up to 20 years. These schedules can result in significantly better compliance and cost-effectiveness of the vaccination programs.
